Differential phase contrast imaging using a Talbot-Lau-type interferometer has been studied extensively over the last few years with respect to the potential benefit for diagnostic imaging, in particular in the area of orthopedics and mammography. This imaging method provides in addition to the conventional image of X-ray attenuation two further images, namely the differential phase contrast image, reflecting information of the electron density within the imaged object, and the dark field image, where the contrasts are created by small angle scattering. In particular the dark field signal/image gained considerable interest lately, since there is evidence that micro-calcifications show up at a very early stage in this image, even before the calcifications are large enough to become visible in the attenuation contrast images, and there is evidence that the dark field signal can be used to classify different types of calcifications.
Another forthcoming technology in medical X-ray imaging is the use of energy resolving photon counting detectors. In the area of attenuation contrast imaging, the use of the detector type allows to discriminate between attenuation of the X-ray due to the photo-electric effect and Compton scattering. It further allows providing an attenuation contrast image with improved contrast to noise ratio by means of so-called energy weighting [P M Shikhaliev, “Projection x-ray imaging with photon energy weighting: experimental evaluation with a prototype detector”, Physics in Medicine and Biology 54(16):4971-4992 (2009)]. A similar concept has been used in the area of differential phase contrast imaging [G Pelzer et al, “Grating-based x-ray phase-contrast imaging with a multi energy-channel photon-counting pixel detector”, OPTICS EXPRESS, 4 Nov. 2013, Vol 21, No 22, pp 25677-25684] and dark-field imaging [G Pelzer et al “Energy weighted x-ray dark-field Imaging”, OPTICS EXPRESS, 6 Oct. 2014, Vol. 22, No. 20, pp 24507-24515], where energy weighting may also improve the signal to noise ratio.